Veteran ape-leader Caesar faces off against humans in War for the Planet of the Apes, the third chapter in the smart Planet of the Apes reboot series.

Chimpanzee Caesar (motion-capture performance by Andy Serkis) has led the apes through a long war with the humans. (Previously on Apes: Caesar and other apes were given drugs that allowed for human-like intellectual advancement and, for some apes, speech. The same lab also unintentionally let loose a virus that wiped out most of humanity. An uneasy detente between remaining humans and the advanced apes eventually turned into open war.)

Both apes and humans believes the other side aims to wipe them out. Humans, led by a man called the Colonel (Woody Harrelson), are aided in their efforts by apes they call “donkeys,” many of whom were one-time followers of Koba, the ape who escalated the human-ape conflict in the second movie.

The apes capture a group of human soldiers after one skirmish. Caesar decides, instead of killing them, to send them back to the Colonel. He hopes to prove that he and the apes aren’t “savages,” and to forge a truce: leave the apes alone in the woods and the violence can end.

The Colonel, of course, does not do this. Instead, he attacks the apes’ home base (the location provided by an ape turncoat). The attack has devastating consequences for Caesar, who must now decide what to do with both the remaining apes in his community and his own growing hate toward the Colonel. Eventually, he sets out with old friends the orangutan Maurice (Karin Konoval), the gorilla Luca (Michael Adamthwaite) and fellow chimpanzee Rocket (Terry Notary) to find the Colonel. Along the way, they make surprising discoveries including the existence of an ape outside their group, a zoo chimpanzee who calls himself Bad Ape (Steve Zahn), who can also talk, and a human girl, eventually called Nova (Amiah Miller), who can’t talk. They find other humans who can’t vocalize, suggesting that the human-ape war might not be the only threat to people.

When your society, perhaps even your species, faces an existential threat, what do you do — make war or make peace? Which one will get you to your goal of survival? And, deep down, is survival always as motivating as revenge?

These are the questions this movie asks. This might be a sci-fi action movie where more than half the core cast are motion-capture creations but this is not a frivolous movie. Its characters — human and ape — are mired in grief and fear and staring at the possible end of their world. These are big thoughts and emotions and the movie is able to match the weight of this while still having moments of lightness and humor. And it gives characters space to think without feeling draggy or padded. It is pretty to look at and it uses its cinematography to tell the story, not just pretty it up.

I’ve seen other reviews describe this movie as a Western, a prison movie and a quest movie. I’d also add biblical epic (though less campy than that genre usually is). This movie has elements of all of these genres and some solid action and manages to be at times fun, serious, emotional and light, all without ever being silly. And I think you have to credit the performances for this — not just Serkis, who is great as always. But also Harrelson, who tempers his craziness, and Karin Konoval’s Maurice, who communicates primarily in sign and with Maurice’s expressive eyes and plays the moral center of Caesar’s world beautifully, allowing for some real wrestling with the nature of humanity and morality.

War for the Planet of the Apes is a very strong entry in what has always been a strong series, one that has far more impact than you expect from a movie with so much genuinely exciting action, a nice thinky sci-fi concept and just the right dashes of humor. A

Rated PG-13 for sequences of sci-fi violence and action, thematic elements and some disturbing images. Directed by Matt Reeves and written by Mark Bomback & Matt Reeves, War for the Planet of the Apes is two hours and 20 minutes long and distributed by 20th Century Fox.